Suppose we construct \((n,k)\)  polar code \(\mathcal {C}\)  with kernel \(K\) . Let \(P_e(n)\)  be a block error probability of \(\mathcal {C}\)  under transmission over \(W\)  and decoding by SC algorithm. It was proven [1]}, that if \(n/k <\ I(W)\)  and \(\beta < E(K)\) , then
\(P_e(n) \le 2^{-n^\beta }.\)
